Fuser apparatus

ABSTRACT

Support for a lamp used in a fuser apparatus in which the terminal of the lamp is held in a convoluted central portion and is supported by arcuate legs. An electrical connector is attached to the lamp terminal through aligned apertures in spaced arms of the connector which are compressed toward each other by a screw.

United States Patent 1 91 1111 3,869,696 Snowden Mar. 4, 1975 FUSER APPARATUS 2,642,52l 6/1953 Easter 219/343 x 3,143,629 8/l964 A el et al. 240/5l.ll R [751 lnventorl Charles Smwdem Falrpor" 3,213,272 10/1965 L l ikemper et a! 240/5111 R [73] Assignee; Xerox Corporation, Stamford, 3.786247 1/1974 11m et al. 240/113 Conn. 22 Filed; S 20 1973 Primar v Eraminer-Richard L. Moses [21] Appl. No.: 399,020

Related US. Application Data [57] ABSTRACT [62] Division of Ser. No. 250,671, May 5, i972.

Support for a lamp used 1n a fuser apparatus 1n wh1ch 521 U.S. c1. 240/52 R, 240/5111 A the terminal of the lamp is held in a convoluted 151 1m. 01. F2lv 21/00 Portion and is Supported by mum legs- Ari-91w [58] Field of Search H 240/52 R, 114 R, 51.11 trical connector is attached to the lamp terminal 2 0/521. 1.3; 219/342, 343 through aligned aperturesin spaced arms of the connector which are compressed toward each other by a [56] References Cited screw UNITED STATES PATENTS 4 Claims, 5 Drawing Figures 2.287.276 6/1942 Runge 240/5l.l1 R

PAIENIEB R SHEET 1 [If 2 PATENTEDHAR 4197s sum 2 or 2 v3 L l w 96 m 65 o FUSER APPARATUS This is a division, of application Ser. No. 250,671, filed May 5, 1972.

BACKGROUND OF THE INVENTION This invention relates to electrostatography, and more particularly to an improvement in the fusing apparatus of an electrostatographic recording apparatus. This invention further relates to a support for a lamp. This invention also relates to an electrical connector for a lamp.

Electrostatography is exemplified by the basic electrophotographic process taught by C. F. Carlson in U.S. Pat. No. 2,297,691, which involves placing a uniform electrostatic charge on a photoconductive insulating layer, exposing the layer to a light and a shadow image to dissipate the charge on the areas of the layer exposed to the light and developing the resulting latent electrostatic image by depositing on the image a finely-divided electroscopic material referred to in the art as toner. The toner is normally attracted to those areas of the layer which retain a charge, thereby forming a toner image corresponding to the latent electrostatic image, which may then be transferred to a support surface, such as paper. The transferred image is generally permanently affixed to the support surface by heating, although other suitable fixing means, such as solvent or overcoating treatment, may be substituted for the heat fixing step.

In general, the powder image is affixed to a transfer sheet by a heat fusing technique and among such techniques there may be mentioned oven fusing, hot air fusing, radiant fusing, flash fusing and the like. Flash fusing is a highly desireable fusing technique in that such a technique is efficient for both normal and high speed copying. Flash fusing is generally effected by the use of a gas lamp, such as a Xenon lamp, from which radiant energy is directed onto the surface ofa recording sheet, containing a powder image, conveyed past the lamp. Theradiant energy is reflected by those areas of the recording sheet which do not bear toner, while the toner on the other areas of the recording sheet absorb the radiant energy in the form of heat which is sufficient to effect the desired fusing.

In such fusing apparatus, the lamp must be connected to appropriate electrical circuitry and accordingly, there is a need for a connector which provides a firm electrical connection and can be easily removed to provide for servicing of the lamp. Similarly, there is a need for a means for supporting the lamp which can be easily removed to provide for servicing of the lamp and which does not interfere with the desired operation of the fusing apparatus.

SUMMARY OF THE INVENTION An object of the invention is to provide an improved fusing apparatus.

Another object of the present invention is to provide for an improved support for a lamp.

A further object of the present invention is to provide an improved electrical connector for a lamp.

Still another object of the present invention is to provide an imporved support for a lamp used as a source of high intensity radiation in a fusing apparatus.

Yet a further object of the present invention is to provide an improved electrical connector for a lamp used as a source of high intensity radiation in a fusing apparatus.

These and other objects of the present invention should be apparent to those skilled in the art from the following description of the present invention.

The objects of the present invention are accomplished in one aspect by providing a support for a lamp in the form of a retaining clip having a convoluted central portion defining an aperture which is adapted to be fitted over the terminal of a lamp, and axially spaced oppositely curved arcuate outer portions connected to the ends of the central portion which functions as supporting legs for supporting the lamp. More particularly, the retaining clip preferably formed of a single resilient wire is particularly adapted for supporting a lamp used as a source of radiant energy in a fusing apparatus. In such an environment, the arcuate outer portions are preferably equally radially spaced from the central axis of the opening in the central portion of the clip whereby the lamp may be centrally positioned in a cooling tube for the lamp.

The objects of the present invention are furether accomplished, in another aspect, by providing an electrical connector which is particularly adapted to provide an electrical connection with a lamp terminal. The connector includes spaced arms having aligned apertures which are fit over the lamp terminal and a fastening means for compressing said arms towards each other to provide a firm connection between the arms and the lamp terminal.

The object of the present invention are still further accomplished in a further aspect by providing a fusing apparatus in which a lamp is supported in a cooling tube by the hereinabove described retaining clip and is connected to appropriate electrical circuitry through the hereinabove described electrical connector.

The invention will be further described with respect to an embodiment thereof illustrated in the accompanying drawings.

The Drawings FIG. 1 is a simplified schematic representation of electrophotographic apparatus including an embodiment of the present invention;

FIG. 2 is a side elevational view of an embodiment of the fuser of the present invention;

FIG. 3 is a cross-sectional view taken along the line 3-3 0f FIG. 2;

FIG. 4 is an elevational view of an embodiment of the support of the present invention;

FIG. 5 is an elevational view of an embodiment of the electrical connector of the present invention.

DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings, there is shown schematically in FIG. 1 an embodiment of the subject invention in a suitable environment such as an electro photographic reporducing machine adapted for continuous and automatic operation. The machine includes an electrophotographic plate or surface 10 formed in the shape of a drum. The plate has a photoconductive or light responsive layer on a conductive backing, jour naled in a frame to rotate in the direction indicated by the arrow. The rotation will cause the plate sequentially pass a series of electrophotographic processing stations. For the purpose of the present disclosure, the several electrophotographic processing stations in the path of movement of the plate surface may be described functionally as follows:

A charging station A at which a uniform electrostatic charge is deposited on the photoconductive plate;

An exposure station B at which a light or radiation pattern of the copy to be reproduced is projected onto the plate surface to dissipate the charge in the exposed areas thereof to thereby form a latent electrostatic image of-the copy to be produced;

A developing station C at which electrostatographic developing material, including toner particles having an electrostatic charge opposite that of the latent electrostatic image is cascaded over the plate surface whereby the toner particles adhere to the latent electrostatic image to form visible toner image in a configuration of the copy being reproduced;

A transfer station D at which the toner image is electrostatically transferred from the plate surface to a transfer material or a support surface and A drum-cleaning station E at which the plate surface is brushed to remove residual toner particles remaining thereon after image transfer and exposed to a relatively bright light source to effect substantially complete discharge of any residual electrostatic charge remaining thereon.

It is felt that the preceding description of the electrophotographic process is sufficient for an understanding of the instant invention. Further details of this type of electrophotographic apparatus may be had be references to U.S. Pat. No. 3,301,126 issued to R. F. Osborne, et al.

In addition to the apparatus disclosed in aforementioned Osborne et al patent, the electrophotographic machine is also provided with fixing apparatus to permanently bond the toner image to the backing sheet and which forms the basis of the instant invention.

The sheet material, preferably paper, which is to form the final support for the permanent toner image, as shown. is a web of material 12 wound about a support roll 14 at a supply station. The web is directed along a feed path to pass the transfer station D and guided by an idler roller 22 through a light attenuator 23 described in detail to copending U.S. application Ser. No. 250,636 P/2331 filed concurrently herewith and into the flash fuser assembly 100 of the present invention. The web having the fused image thereon is guided from the flash fuser assembly by a roller for ultimate withdrawal from the machine. The web may be subsequently cut into sheets as known in the art.

The fuser assembly 100 includes a fuser housing 101 comprised of an upper section 102, defining a top wall 103, side walls 104 and 105, front wall 106 and a rear wall 107, and a lower section 108, defining a bottom wall 109. The bottom of the front and rear walls 106 and 107 of the upper section 102 are provided with outwardly extending longitudinal flanges 111 and the bottom section 108 is provided with longitudinal spacing bars 112 which extend parallel to the flanges 111 and are affixed thereto by suitable fastening means, such as screws 113. In this manner, the bottom wall 109 is spaced from each of the side walls 104 and 105 to define therebctween transfer sheet inlet and outlet slits I14 and 115, respectively, for introducing and withdrawing a transfer sheet into and out of the fuser-housing 101. The side wall 105 is further provided with a resilient seal means 116 which extends over the outlet slit 115 and is in contact with the bottom wall 109, with the transfer sheet being withdrawn from the housing 101 between the seal means 116 and the bottom wall 109. The seal means 116 is provided to inhibit leakage'of light from the fuser.

The interior of the upper section of the fuser housing 101 is provided with an inner liner or shell 117 integrally connected to the upper section 102 and spaced therefrom to provide an insulating air gap 118 therebetween. The inner surface 119 of the shell'117 is provided with a light reflecting surface to maximize the transfer of heat to the transfer sheet being passed through the flash fuser housing 101.

The fuser heating assembly 121 is comprised of a high intensity radiation source such as a pair of spaced flash lamps 122 each centrally positioned in cylindrical glass cooling tubes 123 which are positioned transverse to the path of a transfer sheet through the fuser housing and which extends through aligned apertures 124 in the front and rear walls of the housing 101. An insulating tube 125, formed of a suitable insulating material, is telescopically received over the ends of each of the cooling tubes 123 and includes a collar receiving exterior radial flange 126 and an O-ring receiving interior circular shoulder 127. A fastening collar 128 is received over the flange 126 of insulating tube and is removably fastened to the housing 101 by suitable fastening means, such as screws 129. An O-ring 131 is positioned on the shoulder 127 of insulating tube 125, and is seated into sealing contact with the shoulder 127, housing 101 and cooling tube 123 by tightening of the screws 129 on collar 128.

The flash .lamps 122 may be of a type known in the art, such as a quartz tube filled with a suitable gas, such as Xenon gas. The flash lamp 122 includes axially spaced electrodes 171 and a trigger coil 172 wrapped around the exterior of the gas filled tube. The trigger coil 172 is connected to a trigger circuit, of a type known in the art, which when activated provides a suitable high voltage pulse to the trigger coil 172. The operation of the flash lamp is well-known in the art and no detailed explanation thereof is deemed necessary for a full understanding of the present invention. Further details with respect to flash fusing lamps may be obtained by reference to U.S. Pat. No. 3,465,203; U.S. Patent No. 3,445,626; and U.S. Pat. No. 3,529,129.

The flash lamps 122 are cooled by a coolant, preferably air obtained from the atmosphere, circulated through a cooling circuit which includes cooling tubes 123 and a pair of parallel transverse tubular return ducts 181 affixed to the outer portion of the lower section 108. The insulating tubes 125 positioned on the rear wall 107 of housing 101 are connected through suitable duct work in fluid flow communication with a source of cooling air under pressure, such as a centrifugal blower which obtains cooling air from the atmosphere, and the insulating tubes 125 positioned on the front wall 106 of housing 101 are in fluid flow communication with the return ducts 181 through removable right angle connectors 182 and 183. The return ducts 181 are in fluid flow communication with suitable ducts for withdrawing the cooling air from the machine. In this manner, cooling air obtained from the atmosphere may be circulated around the flash lamp 122 and subsequently returned to the atmosphere.

In accordance with the embodiment as illustrated, each of the cooling tubes 123 at the portion thereof within the housing 101 adjacent to the rear wall 107 is provided with a small aperture whereby air under pressure is introduced into the interior of housing 101. The small quantity of air introduced into the housing 101 circulates through the housing and is released therefrom through the recording sheet inlet and outlet slits 114 and 115. In this manner, the interior of the housing 101 is maintained under positive pressure and such positive pressure functions to maintain the interior of the housing essentially free of any machine or atmospheric dirt which could normally enter the housing 101.

In accordance with the present invention there is provided a support means in the form of resilient clips 141 which are particularly suited for supporting the flash lamps 122 in the cooling tubes 123.

Referring to FIG. 4, clips 14] are comprised of a single resilient wire formed into a convoluted central portion 143 defining a cylindrical opening 144, axially spaced oppositely curved arcuate outer portions 145 and 146, which functions as supporting legs, connected to the axially spaced ends of the central portion 143 by curved intermediate portions 147 and 148. The arcuate outer portions 145 and 146 are preferably each curved about equal radii having their respective centers along the central axis of the cylindrical opening 144 with each of the radii such that the flash lamps 122 are positioned at about the center of the cooling tube 123.

The flash lamps 122 are mounted in the retaining clips 141 by spreading the top of the outer portions 145 and 146 to enlarge the opening 144 and placing the terminals 142 into the enlarged opening 144. Releasing of the outer portions 145 and 146 of the clip 141 results in the central portion 143 gripping the terminals 142 of the flash lamp 122. The design of the clip 141 is such that the clip 141 does not impede the flow of coolant through tubes 123. The support legs defined by the arcuate outer portions 145 and 146 as particularly shown, are supported in the insulating tube 125, but it is to be understood that the retaining clip could be positioned in the cooling tube 123.

In accordance with the present invention there is fur ther provided an electrical connector, generally indi cated as 151 which is particularly suited for connecting the terminals of the flash lamp to an electrical circuit. Referring to FIG. 5, the electrical connector 151 is comprised of axially spaced parallel vertical arms 152 and 153 connected to each other by a horizontal con necting base 154 whereby the connectors 151 have a generally Ushape. The arms 152 and 153 are provided with axially spaced aligned apertures 155 and 156 which are slidingly fit over the lamp terminals 142. The upper ends of the arms 152 and 153 are provided with aligned screw holes adapted to receive a screw 157 whereby the axis of the screw is parallel to the lamp terminal. The tightening of screw 157 causes the ends of arms 152 and 153 to move axially toward each other, thereby changing the effective diameter of the apertures 155 and 156, and providing a gripping connection between the connector 151 and the metal terminal 142. An electrical wire 158 which enters the interior of the insulating tube 125 through an aperture 159 including a suitable seal, such as O-ring 161, is removably fastened to the base 154 of connector 151 by a suitable fastening means, such as a screw 162. In this manner, the lamp terminals 142 are facilely connected to a suitable circuit and the electrical connection may be readily removed by the use of a screw driver which can easily be inserted into the insulating tubes 125.

In operation, a recording sheet having a toner image thereon is passed through the fuser housing, and the flash lamps are operated in a timed sequence as known in the art, to insure fusing of the toner image thereon. Air is circulated by the centrifugal blower through the cooling tubes 123 and a small quantity thereof is intro duced into the housing through the aperture in the cooling tube to maintain the housing at a positive pressure. In this manner, excess heat is effectively dissipated and the housing is maintained free of foreign contaminants which could reduce the reflectance from the interior surfaces thereof.

The present invention is not limited by the hereinabove described embodiments thereof.

Thus, for example, the support could be used for a lamp other than a lamp used as a heat source in a fusing apparatus. Similarly, the electrical connector may be employed as a connector for a lamp other than a lamp used as a heat source in a fuser.

It is also to be understood that although the present invention has been particularly described with respect to an electrophotographic reproducing machine using a rotating drum as a recording surface, the present invention may also be employed in machines employing other types of recording surfaces; e.g., a rotating belt.

It is further to be understood that the present invention is also applicable to electrostatographic processes other than the electrophotographic type, such as for example, electrostatic processes in which an e electrostatic latent image is formed by a pulsing electrode.

The above modifications and others should be apparent to those skilled in the art from the teachings herein.

The present invention is particularly advantageous in that the support for the lamp as a result of its predetermined dimensions effectively positions the lamp at the desired location each time the lamp is inserted into the cooling tube. In addition, the support is easily constructed at a low cost. Furthermore, the support effectively supports the lamp without excessively impeding the flow of air through the cooling tube. Moreover, the support is easily attached and detached from the lamp. In regard to the electrical connector, such a connector offers the primary advantage of being easily applied to a lamp terminal in a manner to provide a firm electrical connection.

These and other advantages of the present invention should be apparent to those skilled in the art from the teachings therein.

Numerous modifications and variations of the present invention are possible in light of the above teachings and, therefore, within the scope of the appended claims the invention may be practised other than as particularly described.

What is claimed is:

1. In apparatus wherein an elongated lamp is supported at each end by a support member within a lamp housing, an improved lamp support member comprising:

a convoluted central portion defining an aperture for receiving a lamp terminal and axially spaced oppositely curved arcuate outer portions connected to the axial ends of said central portion for supporting said lamp within said lamp housing.

3,869,696 7 8 2. The support of claim 1 wherein said convoluted 4. The lamp support as defined in claim 1 wherein Central Portion and Said axially Spaced outer portions said outer portions are adjustably positionable whereby are comprised of a unitary resilient member. the Size of Said a erture is in r d t u 3. The support of claim 2 wherein said outer portions p c ease m1 la y recewe are about equally radially spaced about centers on the 5 Said lamp terminalaxis of said central portion. 

1. In apparatus wherein an elongated lamp is supported at each end by a support member within a lamp housing, an improved lamp support member comprising: a convoluted central portion defining an aperture for receiving a lamp terminal and axially spaced oppositely curved arcuate outer portions connected to the axial ends of said central portion for supporting said lamp within said lamp housing.
 2. The support of claim 1 wherein said convoluted central portion and said axially spaced outer portions are comprised of a unitary resilient member.
 3. The support of claim 2 wherein said outer portions are about equally radially spaced about centers on the axis of said central portion.
 4. The lamp support as defined in claim 1 wherein said outer portions are adjustably positionable whereby the size of said aperture is increased to initially receive said lamp terminal. 